Life is like an anvil, the more it is struck, the more sparks it emits. —— Galileo

All reasoning must be derived from observation and experiment. ---Galileo

Truth has such power that the more you try to attack it, the more your attacks will enrich and prove it. —— Galileo

The pursuit of science requires special bravery, and thinking is the greatest happiness of mankind—— Galileo

Life is like an anvil, the more it is struck, the more sparks it can emit—— Galileo

You cannot teach others anything, you can only help others discover something - Galileo

Science is not a one-man career - Galileo

Truth Not in the dusty authoritative works, but in the great wordless book of the universe and nature - Galileo

The world is a book written in the language of mathematics - Galileo

"Give me a fulcrum and I can lift the earth!"

Two thousand one hundred and ninety years ago, in the ancient Greek country of Syracuse in Sicily, a great physicist appeared Home. His name was Archimedes (287-212 BC). Archimedes was diligent and studious throughout his life, dedicated himself to science, and was loyal to his motherland. He was respected and praised by people. Archimedes discovered the law of the lever and Archimedes' law is named after him. And used these laws to design a variety of machinery to serve the people and the motherland. Details of his life cannot be verified. But the stories about his inventions and defense of the motherland have been passed down to this day.

The establishment of the law of leverage

People have been using leverage since ancient times and know how to use it skillfully. When the pyramids were being built in Egypt, slaves used levers to lift heavy stones. Shipbuilders used levers to erect masts on ships. People used water booms to get water from wells, etc. But why does leverage do this? Before Archimedes discovered the law of the lever, no one could explain it. At that time, when some philosophers talked about this issue, they insisted that it was "demonic nature". Archimedes did not admit that there was any "demon nature". He understands that various phenomena in nature always have natural reasons to explain them. Leverage had its natural causes, too, and he was determined to explain them. After repeated observations, experiments and calculations, Archimedes finally established the law of balance of levers. That is, "the moment arm is inversely proportional to the force (weight)." In other words, the small weight is one-thousandth of the large weight, and the long moment arm should be several times as long as the short moment arm. After Archimedes established the law of the lever, he deduced that as long as the appropriate lever length could be obtained, any weight could be lifted with very little force. It is said that he once said such heroic words:

"Give me a fulcrum, and I can lift the earth!"

After hearing this, the King of Syracuse said to Archimedes Said: "By Zeus (Zeus is the king of gods in Greek mythology, in charge of sky, thunder, lightning and rain), what you said is really weird, Archimedes!" Archimedes explained to the king After understanding the characteristics of the lever, the king said: "Where can I find a fulcrum to lift the earth?"

"There is no such fulcrum." Archimedes replied.

"Then it is impossible to make people believe in the power of mechanics?" said the king.

"No, no, you misunderstood, Your Majesty, I can give you other examples." Archimedes said.

The king said: "You are too bragging! You can push a heavy thing for me and see what you say." At that time, the king had a difficult problem, that is, he built a heavy object for the king of Egypt. A very big ship. After the ship was built, the entire city of Syracuse was mobilized, but they could not push it into the water. Archimedes said: "Okay, let me push this boat for you."

After Archimedes left the king, he used the principles of levers and pulleys to design and manufacture An ingenious piece of machinery. After everything was ready, Archimedes invited the king to watch the ship being launched. He handed the end of a thick rope to the king and asked him to pull gently.

Suddenly, the big ship slowly moved and slid into the water smoothly. The king and ministers were amazed to see such a miracle, as if they were watching a magic trick! So, the king believed in Archimedes and issued a proclamation to the whole country: "From now on, no matter what Archimedes says, you must believe him..."